1. Field of the Invention
The invention relates to a probe applicator for positioning a bipolar electrosurgical probe having a bendable distal probe end that has a probe tip with a bipolar electrode head, which is connected to two electrical conductors housed in a flexible probe casing, and having a shaft tube in which the probe is housed, and a handpiece that allows the probe end to be flexed selectively.
2. Description of the Related Art
Probe applicators are used, for example, as bipolar vaporization probes (for percutaneous nucleus therapy) in minimally invasive surgery (MIS) procedures for treatment of herniated spinal disks.
A probe applicator for positioning a bipolar electrosurgical probe with a bendable distal probe end is known from EP 1 607 061 B1. The distal probe end has a probe tip with a bipolar electrode head, which is connected to two electrical conductors housed in a probe casing. The probe is longitudinally displaceable in a tube by means of a handpiece. The probe end can be flexed by using the handpiece. The distal end of the probe casing is pre-curved and when covered by the distal shaft tube end, is tensioned into an extended position.
The probe applicator disclosed in EP 1 607 061 B1 is disadvantageous in that the probe casing itself has a pre-curved form or tensioning. It is further disadvantageous that relatively high shear forces act on the outer conductor (electrode) when two conductors are arranged parallel to one another, especially with very pronounced curvature. Once the probe tip is brought into its extended, straight position, i.e. not deflected vis-à-vis its longitudinal axis, this results in compression of the outer electrode, which places stress on the outer electrode. Moreover, the relative motion between the probe and outer tube is hindered due to increased friction.
Furthermore, a similar probe applicator is known from DE 600 28 863 T2, in which the probe casing has a pre-tensioned, curved form. In this case, the probe casing is to be made of a material that can be pre-curved and has sufficient memory to maintain its pre-curved form when the probe casing and/or probe is extended outwards from the opposite-acting outer tube. This probe applicator also has the disadvantages described above.
The present invention seeks to simplify the design of the pre-tensioned curvature of the probe tip and to reduce the stress on the outer electrode, in particular, in the event of compression.